drm/nouveau: Free nv04 instmem ramin heap at card takedown

Add a missing nv04 instmem ramin heap shutdown call.
Signed-off-by: Jimmy Rentz <jb17bsome@gmail.com>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nv04_instmem.c

@@ -95,6 +95,9 @@ nv04_instmem_takedown(struct drm_device *dev)
 	nouveau_ramht_ref(NULL, &dev_priv->ramht, NULL);
 	nouveau_gpuobj_ref(NULL, &dev_priv->ramro);
 	nouveau_gpuobj_ref(NULL, &dev_priv->ramfc);
+
+	if (drm_mm_initialized(&dev_priv->ramin_heap))
+		drm_mm_takedown(&dev_priv->ramin_heap);
 }
 
 int